Beams are joined by welding, bolts, clamps, adhesives, screws, nails and other means. Welding produces a strong, stable joint. However, welding of structural aluminum alloys such as 6061-T6 and others is expensive and time-consuming. The weld requires post-weld heat treatment, and can sometimes crack during treatment or in use. This increases costs of manufacturing aluminum structures.
For example, a bike carrier may be supported from a drawbar in a trailer hitch receiver on a motor vehicle. Strength and durability are needed in a joint between the drawbar and a crossbar supporting the bike carrier. Bolts can be used, but eliminating play requires a clamping action of the crossbar opening on the drawbar. Two vertical bolts through the crossbar may straddle the drawbar and compress the drawbar by reducing the opening via slots in the crossbar. This is taught in a related patent application of the present inventor U.S. Ser. No. 15/396,710 filed Jan. 2, 2017.
The present invention provides an improved connection apparatus that does not require slots in the crossbar, only requires one bolt, minimizes machining, and firmly and reliably locks the drawbar to the crossbar without welding.